Medical researchers from the University of Alberta in Edmonton, Canada, may be a step closer to understanding the causes of a severe cardiac condition known as ventricular fibrillation through a series of high-resolution movies that show how the condition disrupts the heart's normal electrical signals. The movies show that a series of spiral waves originate from the surface of the heart. The waves expand and move over the heart muscle, causing irregular contractions in the cells.The movies show that a series of spiral waves originate from the surface of the heart. The waves expand and move over the heart muscle, causing irregular contractions in the cells. The system uses fluorescent dyes that react to electrical changes in the heart cells. High-intensity lights shine on the heart, then researchers image and intensify specific wavelengths of light that trigger the dyes. The system produces information from 16,000 points on the exterior surface of the heart, operating at 838 frames per second. The high speed enables researchers to capture the rapid and disorganized waveforms for analysis.